In Silverlight, you cannot connect to a database directly. You can create visually appealing interfaces, handle events, make user controls , use all logic and .net framework , but you cannot connect directly to a database.
To access data, the Silverlight application needs to call a Web service, which supplies it with data. The Windows Communication Foundation (WCF) provides you a way to access all your databases by writing all the data access logic within it, and your silverlight application can request data from this WCF service.
Before we create a WCF service, you need to keep in mind that the Web service and the Silverlight application are different applications , that merely exchange data. I am going to show you how to create your first WCF service .
There are only two topics which will be covered in this lesson.
1. Creating the WCF service.
2. Modifying the WCF service.
3. Publishing the WCF service
Step 1: Creating the WCF service
1. Open Visual Studio -> New Project -> WCF -> WCF Service Application.
Name it as MyDataService , and click OK.
2. Open Solution explorer, present to the right of the screen and double click on IService1.cs
You will find an Interface and a class there.
3. The methods in the interface have an attribute [OperationContract] , which is used to specify that this method can be called from the Silverlight application.
4. The class has an attribute [DataContract] , which indicates that this class object can be sent from the WCF service to the Silverlight application and vice versa.
5. Only the members of the class which have [DataMember] attribute will be accessible in the silverlight application.
6. The methods defined in the interface are implemented in the Service1.cs file , which is obtained by expanding the Service1.svc in the Solution Explorer.
7. If you want to create your own class, with its data members, you need to give the [DataContract] attribute to that class also , and its members should be given [DataMember] attribute.
Step 2 : Modifying the WCF service
1. We will create a new method in the interface IService1. Add the following code in it
[OperationContract]
int getStatus(string name);
2. Now save this, and go to Service1.svc.cs . We need to implement the new method defined in the interface. So add the following code there
3. That all :) You have created your web service. You can call this getStatus method, which takes a string as a parameter, and returns you the status as 1 if length is greater than 10 , and 0 if lesser.
How to actually use these WCF services will be covered in the next lesson. For a more detailed explanation and examples, check this video.
To access data, the Silverlight application needs to call a Web service, which supplies it with data. The Windows Communication Foundation (WCF) provides you a way to access all your databases by writing all the data access logic within it, and your silverlight application can request data from this WCF service.
There are only two topics which will be covered in this lesson.
1. Creating the WCF service.
2. Modifying the WCF service.
3. Publishing the WCF service
Step 1: Creating the WCF service
1. Open Visual Studio -> New Project -> WCF -> WCF Service Application.
Name it as MyDataService , and click OK.
2. Open Solution explorer, present to the right of the screen and double click on IService1.cs
You will find an Interface and a class there.
3. The methods in the interface have an attribute [OperationContract] , which is used to specify that this method can be called from the Silverlight application.
4. The class has an attribute [DataContract] , which indicates that this class object can be sent from the WCF service to the Silverlight application and vice versa.
5. Only the members of the class which have [DataMember] attribute will be accessible in the silverlight application.
6. The methods defined in the interface are implemented in the Service1.cs file , which is obtained by expanding the Service1.svc in the Solution Explorer.
7. If you want to create your own class, with its data members, you need to give the [DataContract] attribute to that class also , and its members should be given [DataMember] attribute.
Step 2 : Modifying the WCF service
1. We will create a new method in the interface IService1. Add the following code in it
[OperationContract]
int getStatus(string name);
2. Now save this, and go to Service1.svc.cs . We need to implement the new method defined in the interface. So add the following code there
3. That all :) You have created your web service. You can call this getStatus method, which takes a string as a parameter, and returns you the status as 1 if length is greater than 10 , and 0 if lesser.
How to actually use these WCF services will be covered in the next lesson. For a more detailed explanation and examples, check this video.
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